Atrial Dyssynchrony:A New Predictor For Atrial High-Rate Episodes In Patients With Cardiac Resynchronization Therapy

Background: Heart failure may induce atrial dyssynchrony.We aim to investigate whether pre-implantation left atrial(LA)dyssynchrony could predict newly detected atrial high rate episodes(AHRE)after receiving cardiac resynchronization therapy defibrillator(CRT-D).Methods: Retrospective analysis of consecutive patients who received CRT-D for standard indications and without a history of atrial fibrillation.The standard deviation of the time to peak strain in each LA segment during ventricular systole(SDs)and late diastole(SDa)were calculated to quantify LA dyssynchrony using two-dimensional speckle tracking echocardiography before device implantation.Patients were divided into the AHRE group and the AHRE-free group,depending on the presence of AHRE during device interrogation.Results: 31 patients(28%)had newly detected AHRE,during a mean follow-up of 21 ± 9 months.Patients in the AHRE group had higher SDs(8.2 ± 2.6%vs.6.3 ± 2.3%,P < 0.001)and SDa(5.4 ± 1.8% vs.4.1 ± 1.4%,P < 0.001)values before implantation than patients in the AHRE-free group.In the multivariate logistic analysis,both SDs(OR 1.325,95% CI: 1.074 – 1.636,P = 0.009)and SDa(OR: 1.499,95% CI: 1.071 – 2.098,P = 0.018)were independent predictors of newly detected AHRE.At a cut-off value of 7.4%for SDs and 5.3% for SDa,the Kaplan-Meier survival analysis showed that patients with higher SDs and SDa had significantly increased risks of newly detected AHRE after receiving CRT-D.Conclusion: Dyssynchronous LA lengthening and contraction could assist in the prediction of newly detected AHRE in patients with CRT-D.